unconscionable

unconscionable \uhn-KON-shuh-nuh-buhl\, adjective:

1. not influenced or guided by conscience
2. very great

Hastert also took aim at the rich pay package for Exxon Mobil Corp.'s retired chief executive, which he called "unconscionable."
-- Steven Mufson and Timothy Dwyer, The Washington Post, 2006-04-22

THE U.S. SUPREME Court on Wednesday executed an unconscionable U-turn on abortion, upholding a restrictive federal law that is virtually indistinguishable from a Nebraska statute it struck down only seven years ago.
-- LA Times, 2007-04-19

by 1570, "showing no regard for conscience," from un- (1) + now rare conscionable "conscientious" (1549), from conscioned "having a conscience."